Page:The Habitat of the Eurypterida.djvu/22

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THE HABITAT OF THE EURYPTERIDA

A recent discovery by Professor Gilbert van Ingen has brought to light some eurypterid remains from a loose block found lying in Oriskany Creek, 3 miles south of Clinton, New York. Three carapaces and several other fragments were found, the block also being "full of lingulas and orbiculoideas" (39, 421). A new species, Eusarcus vaningeni Clarke and Ruedemann was made, to include these specimens which closely resemble E. cicerops of the Shawangunk of Otisville and may represent the adult of that species.

From the shale beds in the Shawangunk conglomerate at Otisville, Orange County, New York, a large fauna of eurypterids has been obtained, but other fossils except Ceratiocaris are absent. Here in the Shawangunk Mountains of Eastern New York is a great series 630 feet thick of the Shawangunk grit resting upon the Hudson River shales. The series consists of alternating shales varying from 2 to 6 inches in thickness, and conglomerates or sandstones from 1 to 50 feet thick, the shale bands containing the merostomes. Some of the specimens though only 2.5 mm. long "are perfectly preserved and are by far the youngest and smallest yet recorded. In regard to the occurrence Clarke says: "In the Shawangunk section we have a fauna constantly repeating itself through a thickness of 650 feet which elsewhere appears only and briefly at the base of the Salina" (36, 303). The perfect specimens are all of young individuals, adults being represented only by fragments. The species recorded are: 1. Eurypterus maria Clarke, 2. Eusarcus? cicerops Clarke, 3. Dolichopterus otisius Clarke, 4. D. stylonurus Clarke and Ruedemann, 5. Stylonurus (Ctenopterus) cestrotus Clarke, 6. S. (Ctenopterus) sp. α, β, γ, 7. S. myops Clarke, 8. S. sp., 9. Hughmilleria shawangunk Clarke, 10. Pterygotus globiceps Cl. and R.

From the middle part of the Shawangunk grit of Delaware Water Gap, Pennsylvania, intercalated black shales similar to those in New York have furnished eurypterids. These were discovered by Mr. Paul Billingsley of Columbia University, who collected a large amount of material and who reports that the fragments are all dissociated, the carapaces commonly occurring by themselves, and separated from the abdominal segments, as if arranged by violent currents. Professor G. van Ingen and Mr. J. C. Martin have also collected extensively from this section. From their large number of specimens Clarke and Ruedemann have been able to identify Nos. 1, 3, 7, 9, 10 of the list of species recorded from the Shawangunk of Otisville, and they make the comment that "Unfortunately, the maceration,